A dynode is an electrode in a vacuum tube that serves as an electron multiplier through secondary emission. The first tube to incorporate a dynode was the dynatron, an ancestor of the magnetron, which used a single dynode.

What is function of dynodes in photomultiplier tube?

The anode of a photomultiplier tube is an electrode that collects secondary electrons multiplied in the cascade process through multi-stage dynodes and outputs the electron current to an external circuit.

What are dynodes coated with?

A discrete dynode detector consists of an array of discrete dynode multipliers, usually containing 15–18 dynodes, coated with a metal oxide that has high secondary electron emission properties.